1. Field of the Invention
The present invention relates to an automatic tensioner apparatus for applying a tensioning force to a transmission belt or the like of a wrapping connector type transmission mechanism, such as commonly used on automotive engines.
2. Description of the Prior Art
There is a conventionally known automatic tensioner apparatus comprising an idler pulley engaging a transmission belt of the wrapping connector type transmission mechanism, an arm for swingably supporting the pulley on a supporting surface, and a resilient member for exhibiting a resilient force for swinging the arm and idler pulley in a direction to engage the transmission belt.
Such an automatic tensioner apparatus can be used for various applications and, for example, is utilized on an internal combustion engine of an automobile. FIG. 6 is a sectional elevation that illustrates one example of such a conventional automatic tensioner apparatus for use on an internal combustion engine, in which a support shaft 100 is fixed onto a base plate 015 that is fixed to a supporting surface f of an engine block E of the internal combustion engine, and the base portion of an arm 011 is swingably carried on the support shaft 100. An idler pulley 010 is rotatably carried on a tip end of the arm 011 to engage a transmission belt Bs. A resilient member 012 in the form of a coiled spring is disposed between the base portion of the arm 011 and the base plate 015 for biasing the idler pulley 010 at the tip end of the arm 011 in a direction to engage the transmission tension belt Bs. However, behind the base portion of the arm 011, there is not sufficient space to place other functional parts around the automatic tensioner apparatus. Therefore, if the other functional parts, e.g., a transmission belt Bt of another wrapping connector type transmission mechanism is intended to be placed behind the base portion of the arm 011, it is necessary to provide special components to separate the entire automatic tensioner apparatus, including the base plate 015, from the supporting surface f, and to extend the so-called belt line of the transmission belt Bs forwardly, resulting in a problem of increasing the size of the entire apparatus and perhaps the overall length of the engine.